The term 'main part' can be used to describe a variety of different concepts. PLURALITY (9 letters) is the quality or state of being multiple, GROSS (5 letters) is the total amount before deductions, MAJORITY (8 letters) is the greater number or part, BULK (4 letters) is the mass or magnitude of something, BODY (4 letters) is the physical structure of a person or animal, GIST (4 letters) is the main point or ESSENCE of something, LEAD (4 letters) is the initiative or guidance in an activity, PIPE (4 letters) is a tube or conduit for conveying a substance, ESSENCE (7 letters) is the intrinsic nature or indispensable quality of something, KEYSTONE (8 letters) is the central or most important element, PRINCIPAL (9 letters) is the chief or most important person, and Lion's Share (10 letters) is the largest portion or greatest benefit. All of these words can be used to describe the main part of something.